This invention relates to a row crop harvesting header for a combine, a forage harvester, or the like, wherein the header removes row planted crops from the field as the machine advances and delivers it rearwardly to the harvesting machine for further processing. Such a row crop harvesting header is shown in U.S. Pat. No. 3,982,384, which is also assigned to the assignee herein. As described in said U.S. patent, the header includes a plurality of row units that extend forwardly from the main header frame, each row unit being adapted to remove one row of row planted crop material. Each row unit includes a pair of laterally spaced endless flexible conveyors having opposite rearwardly moving inner runs that grasp the crop material to deliver it rearwardly to a further conveying system on the header, a cutting apparatus being provided at the forward end of the conveyors to sever the crop from the field.
When the machine is being used to harvest soybeans or the like, it is desirable to sever the crop as close to the ground as possible and therefore the machine is operated with the forward end of each row unit riding along the ground on the skids at the front of the row unit frame. While some fields are relatively clean, in certain areas, there are numerous rocks lying in the field, while in other fields there are foreign objects such as bricks or tree branches, and when the row units are operated close to the ground, the rocks and foreign objects can damage the cutting apparatus, or in some cases can be engaged by the conveyors, which can be damaged thereby. Also, the conveyors could deliver the foreign object into the harvesting machine, which can cause additional damage.